In the construction of glass block walls or panels, a significant level of skill is required to properly space and align the blocks with respect to each other. Glass block walls are typically assembled on-site by a mason, much in the same way as brick walls are assembled, with mortar spread on exposed edges of the blocks and set into place. However, glass blocks are normally placed and aligned directly above each other, without overlapping as in the construction of brick walls. When assembling glass block panels, it is essential that rather precise spatial relationships between the glass blocks be maintained in order to provide a more structurally sound and aesthetically pleasing panel.
Frequently, mortar has been used to secure the blocks to one another as exemplified in U.S. Pat. No. 2,167,764. However, there are several problems associated with the use of mortar in constructing glass block panels. For instance, the use of mortar requires a skilled mason to accurately determine the amount of mortar to be used, as well as to achieve the proper placement of the mortar in the panel. This increases the amount of time necessary to construct such a panel and requires high levels of training and experience in the work force. In this respect, if the glass blocks are laid too quickly, the weight of the block will tend to squeeze the mortar, misaligning the panel. This results in both an aesthetically displeasing and structurally unsound panel.
Another drawback in the use of mortar is the inadequate bond formed between the mortar and the glass. The mortar does not naturally adhere to the glass, and can result in a more fragile glass block panel. Mortar has essentially no elasticity, making the panel more subject to cracking. Given these drawbacks, the art has been prompted to develop mortarless glass blocks.
Mortarless glass block panels typically include the use of integral spacers interposed between the blocks. Spacers add the benefit of properly aligning the blocks without the necessity of a skilled mason. An adhesive is then applied to the spacers and adjacent blocks to bond and secure the panel. Typically, a clear silicone adhesive is used to caulk in the joints and the outer interfaces of the blocks. Silicone is known to be particularly useful in that it bonds well with glass, yet provides enough flexibility to avoid the cracking problem associated with the use of mortar.
An example of a mortarless glass block assembly is exemplified in U.S. Pat. No. 4,986,048. In that assembly, a continuous flexible spacer member is placed along the horizontal end walls, while separate flexible spacer members are placed in vertical end walls of the glass blocks. An adhesive is placed between the blocks to adhere the spacers and blocks together. The adhesive is applied by a mason who also caulks the joints from the outside. While mortarless glass block panels offer significant advantages over mortar glass block panels, there are various drawbacks associated with such panels. For instance, the rate at which the panels may be assembled is relatively slow. The panel can only be assembled as quickly as the workers lay courses of blocks. In addition, the spacers and adhesive must be applied by a mason with precision, a task which is time consuming, tedious and subject to human error.
In view of the above it is not surprising that there has been a move in the art towards the use of prefabricated glass block panels. A significant benefit to using prefabricated panels is that they are assembled in a controlled setting, where stringent quality control of the assembled panels can be maintained. An example of a prefabricated panel is exemplified in U.S. Pat. No. 5,448,864 to Rosamond. Rosamond discloses the fabrication of a glass block panel from the use of vertical and horizontal frame members for spacing the glass blocks, with the sealant interposed between the blocks and the adjacent frame members. While glass block panels assembled in accordance with the '864 patent offer advantages to the mortarless glass block panels assembled on-site, there remain various drawbacks. For instance, the presence of the spacers in the panel or wall renders it somewhat weaker than if only adhesive is present. Likewise, the costs associated with the production of the integral spacers which remain affixed in the panels and the labor cost associated with the assembly of these panels are rather undesirable. Finally, a significant level of skill is still needed to properly space, align, and place the blocks. This increases cost in terms of both time and personnel.
Accordingly, there is a need in the art for a method and device for prefabricating glass block panels without the use of mortar or integral spacers, while at the same time acquiring quality and strength of the glass block panel, as well as decreasing the time and level of human skill associated with its construction. It is a purpose of this invention to fulfill this and other needs in the art which will become more apparent to the skilled artisan once given the following disclosure.